Inflammation

Question 1

what are the features of inflammation?

Answer 1

• a non-specific response to cellular injury

- a universal process in health and disease

Question 2

what are the four main signs of acute inflammation and how do they occur?

Answer 2

1) Redness (Rubor) - accumulation of RBCs
2) Heat (Calor) - incr. presence of fluid at core body temp at site + high metabolic rate of immune cells
3) Swelling (Tumor) - incr. blood flow into inflamed tissues = fluid build-up
4) Pain (Dolor) - mediators signal nerve cells
5) Loss of function (Functio laesa)

Question 3

What is acute inflammation?

Answer 3

rapid response non-specific response to cellular injury

Question 4

What happens as there is damage in acute inflammation?

Answer 4

1) inflammatory signals released i.e. to non-apoptotic cell death/foreign material\
2) vasodilators - nitric acid + histamine
3) vascular endothelium cause change - vasodilation, plasma leak, incr. permeability, reduce flow of blood.

Question 5

Describe histamine
sources
actions

Answer 5

mast cells, basophils, platelets

vasodilation, incr. vascular permeability, endothelial activation

Question 6

Describe prostaglandins
sources
actions

Answer 6

mast cells, leukocytes

vasodilation, pain, fever

Question 7

Describe cytokines (TNF, IL-1)
sources
action

Answer 7

mast cells, macrophages, endothelial cells

Endothelial activation (adhesion molecules), fever, malaise, pain, anorexia, shock

Question 8

Describe chemokines
sources
actions

Answer 8

Leukocytes, activated macrophages

Chemotaxis, leukocyte activation

Question 9

Describe complement (C5a, C3a, C4a)
sources
actions

Answer 9

Plasma (produced in the liver)

Leukocyte chemotaxis and activation, vasodilation (mast cell stimulation), opsonisation

Question 10

What is exudate?

Answer 10

Fluid, proteins and cells that have seeped out of a blood vessel

Question 11

What is immune cell recruitment?

Answer 11

-Recruitment and inflammation signals at the site of manage e.g. chorines produced

Question 12

What happens during neutrophil extravasation?

Answer 12

1) chemo-attraction e.g. cytokines
2) rolling adhesion
3) tight adhesion
4) transmigration

Question 13

What is the function of a neutrophil at sight of inflammation?

Answer 13

1) Pathogen recognition
2) Pathogen clearance - netosis + phagocytosis
3) cytokine secretion -recruitment of other immune cells

Question 14

What is the resolution of acute inflammation?

Answer 14

1) Pathogen recognition
2) mediators and neutrophils have short half life - turned over rapidly
3) macrophages - clear apoptotic cells + anti-inflammatory mediators
4) repair + wound healing

Question 15

What are the reasons for chronic inflammation?

Answer 15

occurs as a result of a failure in acute inflammation to clear the danger signals:
-Persistent inflammatory stimulii i.e. persistant infection

Question 16

What are the good and bad parts of macrophages?

Answer 16

good:

1) macrophages can be recruited as monocytes and they differentiated in situ
2) Phagocytic
3) Cytotoxic
4) Anti-inflammatory
5) Wound repair

bad:
1) cytotoxins can affect tissues → not very selective
2) pro-fibrotic → promotes wound healing → too much extracellular matrix → scar

Question 17

What are T cell lymphocytes role in inflammation?

Answer 17

1) pro-inflammatory
2) cytotoxic - but selective as they don’t kill surrounding tissues
3) Regulatory

Question 18

What are B cell lymphocytes role in inflammation?

Answer 18

1) Generate plasma cells that secrete antibody.
2) Protective, clearing infection
Inflammatory, driving reactions against self
3) Can either be local to inflammatory site, or operate remotely

(base of all vaccines)

Question 19

What is granulomatous inflammation?

Answer 19

Chronic inflammation with distinct pattern of granuloma formation

• Triggered by strong T cell responses
• t-cells aggregate and fuse around the area

Question 20

What are the features of acute inflammation?

Answer 20

-Immediate onset; lasts a few days
-Vasodilation, increased vascular permeability, leukocyte response
-Neutrophils predominate
-Histamine release
-Prominent necrosis
-Outcomes include:
Complete resolution
Progression to Chronic Inflammation

Question 21

What are the features of chronic inflammation?

Answer 21

-Delayed onset; may last weeks, months or years
-Persistent inflammation, ongoing tissue injury, attempts at healing
-Monocytes / Macrophages predominate
-Ongoing cytokine release
-Prominent scarring
-Outcomes include:
Scarring
Loss of function

Question 22

What are the possible positive outcomes of acute and chronic inflammation?

Answer 22

• Clear inflammatory agent.
• Remove damaged cells
• Restore normal tissue function

Question 23

What are the possible negative outcomes of acute and chronic inflammation?

Answer 23

• Excess tissue damage
• Scarring
• Loss of organ function → organ failure

Question 24

What does wound healing lead to?

Answer 24

extracellular matrix deposition

Question 25

What are the consequences of inflammation?

Answer 25

• Broncho-pneumonia
• Wound healing in sensitive tissues
• Scarring